Technical Field
This disclosure generally relates to a developing device, and a process cartridge and an image forming apparatus, such as a copier, a printer, a facsimile machine, or a multifunction peripheral (MFP) having such a function, that include the developing device.
Description of the Related Art
There are developing devices that include developer containing portions (enclosed by a casing of the developing device), such as a supply portion and a stirring portion arranged in a vertical direction (one above another).
Such a developing device includes an upper developer conveyor (a first developer conveyor), such as a supply screw, to convey developer in the upper developer containing portion and a lower developer conveyor (a second developer conveyor), such as a stirring screw, to convey developer in the lower developer containing portion, respectively. The upper developer conveyor conveys the developer to one side in the axial direction of the developer conveyor, and the lower developer conveyor conveys the developer to the opposite side. The developing device further includes a developer-lifting area in which the developer is lifted from the lower developer containing portion to the upper developer containing portion.